It's weird, but some unnamed team did ask McCoy about his underwear during the NFL Scouting Combine's interview sessions. From ProFootballTalk.com:
"Someone asked me if I wore a g-string or a jock strap when I played," McCoy told the NFL Network set Monday to disbelief, laughter and amazement.
McCoy did not divulge his answer.
I think it's more likely the team wanted to see how McCoy reacted to something unexpected than it is that they were actually curious about his undergarments. The best possible reaction is to probably take it in stride, chuckle, and politely tell them that no, he does not wear a g-string while playing football.
The worst possible reaction is probably to say, "Check this out," and stand up and drop his trousers.
Of course, that wouldn't be any more ridiculous than asking the question in the first place. You ask a silly question, and you open yourself up to a silly answer.
- Gerald McCoy